The story Combined Action Platoons as reproduced on this Web Site, makes the following reference:

The most ambitious Marine pacification program took
root in the summer of 1965. Captain John T. Mullin, Jr., the
civil affairs officer for the 3d Battalion, 4th Marines, based
at Phu Bai, saw an under-used resource in the marines' own backyard.
Mullin thought that the Vietnamese Popular Forces soldiers, a
poorly trained, ill-equipped local militia charged with defending
villages, might be upgraded into an aggressive, effective fighting
force if U.S. Marines took them under their wings. Mullin's idea
impressed his commanding officer, Lieutenant Colonel William
"Woody" Taylor. In July Col. Taylor ordered his executive
officer, Major Cullen C. Zimmerman, to draw up a plan for incorporating
marines into PF units.

In a phone conversation recently, LtCol. Zimmerman (retired) made the following observations:

As one of the earliest Marine units in Vietnam, the 3rd.
Bn., 4th. Marines were sitting ducks at their Phu Bai location.
There were six (6) villages surrounding Phu Bai from which the
Viet Cong continued to harass the Marine unit in Phu Bai.

Recognizing that the Vietnamese peasant was "apolitical",
it was understood that the Marines could not anticipate much
assistance from the villagers. The US Forces needed to "....maintain
a presence to neutralize the V.C. influence..." in those
villages.

LtCol. Zimmerman commented that he "requested" 13 men
from each rifle company. His request specifically stated....not
their best....and not their worst. He indicated his concern, at
the time, that he not "...strip a rifle company of their
best NCOs." However, he also didn't want their "....shit
birds". He did state that he requested one full squad per
company.....(I think).

Each individual was then interviewed by, first, Lt. Paul Ek,
then Maj. Zimmerman himself. One entire "Squad" was
returned to their rifle company. (Apparently somebody
didn't get the word!)

He was curious about the "14 Marines and 1 Navy Corpsman"
mentioned in the Combined Action Platoon story I
sent with the letter. Originally, I believe, he commented that
the first unit was a full Marine platoon. (I could be wrong about
that, but he definitely did not understand the 14 Marines concept.)

During the conversation, LtCol. Zimmerman expressed surprise when
I mentioned the lack of supplies, etc, endured by later CAP Units
on into early to mid-1967. He stated that the first CAC Unit went
into the 'ville with everything they needed for their defense.
I suspect that was the result of this being their "brainchild".
There is more than sufficient evidence that subsequent CAC Units
went into their hamlets with little more than M-14s.

As to why the discrepancies, I would suspect that it was contingent
on the respective battalions who "sponsored" each subsequent
unit, and the degree to which they "bought into" the
program. As we learned from David Sherman's Day One
story, Lt. Gen. Krulak was actively involved in setting up some
of the earlier CAC Units. Perhaps the lack of his "physical"
presence diluted some of the enthusiasm from subsequent battalion
COs.

There was not much else of substance in our phone conversation. LtCol. Zimmerman retired in 1968. He heard
nothing more about the CAP program until he received
my letter recently.

However, he was interviewed by USMC Maj. M.D. Weltsch for a
Master Thesis, and he has suggested that the thesis may be available
from the Command & General Staff College, Fort Leavenworth, KS.